1. Field of the Invention
The present invention relates to an intermittent coating apparatus and an intermittent coating method for intermittently coating a paint to a base material which is running continuously to form intermittent layers thereon.
2. Related Art of the Invention
Japanese Patent Laid-Open No. 7-311997 discloses a coating apparatus for intermittently coating a paint to a base material which is running continuously. This apparatus adopts such a method that winds a base material in a field of batteries around a back roll and disposes a nozzle at a location opposed to the base material, and repeats feeding of the paint to the nozzle and stop of the feeding, thereby forming portions not coated with the paint, that is, lead welding portions on the base material.
However, when a paste for batteries is intermittently coated as a paint to a collector material by the coating apparatus disclosed by Japanese Patent Application Laid-Open No. 7-311997, an active substance layer is coated approximately 30 to 100 mm thick in a section of approximately 20 mm from the coating start terminal of the active substance layer in a running direction of the collector material as shown in FIG. 7, whereby the active substance layer of a thickly coated portion may be peeled off and drop down at a subsequent rolling step. It is considered that this defect is caused by the fact that because a feeding path and a return path are momentarily set to simultaneously opened status at the time of switching the feeding path and the return path at the intermittent time by moving a head used as intermittent means, thereby the paint excessively flows from the return side into the feeding side, or the nozzle. Accordingly, the layer is coated thicker for an amount of the paint which excessively flows into the nozzle at a coating start time.